The Effect Of Different Doses Dexmedetomidine On Tracheal Extubation Response In Patients With Thoracotomy

ObjectivesTo investigate the effect of different doses of dexmedetomidine on controlling mean arterial pressure, heart rate, plasma adrenaline and norepinephrine concentration, recovery time, extubation time after thoracotomy. Effectiveness and optimal dose of dexmedetomidine were evaluated in this experiment.MethodsEighty patients undergoing thoracic surgery were divided randomly into 4 groups:C group (control group), D1 group, D2 group and D3 group.30 min before the end of surgery, patients in C group received 15 ml normal saline, while patients in D1, D2 and D3 groups received 0.25,0.50,1.00μg/kg of dexmedetomidine respectively. Measurements of mean arterial pressure, heart rate, pulse oxygen saturation were performed at TO (before the induction of anesthesia), T1 (before the infusion of dexmedetomidine), T2 (after the infusion of dexmedetomidine), T3 (time of extubation), T4 (1 min after extubation), T5 (3 min after extubation), T6 (5 min after extubation), T7 (10 min after extubation). The 5ml venous blood sample were collected to measure the plasma concentrations of adrenaline and norepinephrine at TO-7 by liquid chromatography.Recovery time and extubation time of erery patient after sergery were recorded. Dysphoria after extubation and adverse reaction in each group were recorded.Results1. The comparison of vital signs. MAP values at T2-6 period were significantly higher when comparing with that at T1 period in C group and D3 group. MAP values at T3-7 period were significantly lower in D2 group when comparing with that in C group. In C group, heart rate values at T2-6 period were significantly higher than that at T1. However, heart rate values were significantly lower at T3-6 period in D2-3 group than that in C group. There is no difference between groups or within group on the values of SpO2.2. The comparison of plasma concentrations of NE and E. The plasma concentrations of NE and E were higher in some degrees in all groups at T3-6 than that at T0, especially in C group and D1 group. The plasma concentrations of NE and E values were significantly lower at T3-6 period in D2 group than C and D1 group.3. The comparison of revive quality.There is no difference between groups or within group at the time of recovery and extubation. (P<0.05)4. The comparison of the adverse reaction.D2 group had fewest adverse reactions,compare with other groups.(P<0.05)ConclusionsThe administration of 0.5ug/kg dexmedetomidine at 30 min before the end of surgery has been found being most effective in controlling haemodynamic responses to tracheal extubation.